Brain-derived neurotrophic growth factor (BDNF) is a protein that is widely expressed in the human brain. The protein plays a critical role in the development and maintenance of neurons in the central nervous system and the peripheral nervous system. For example, BDNF helps to support the survival of existing neurons, and encourage the growth and differentiation of new neurons and synapses. In addition, BDNF has established roles in neuronal survival, differentiation, and synaptic plasticity.
In the brain, BDNF is active in the hippocampus, cortex, and basal forebrain. These areas are vital to learning, memory, and higher thinking. Previous reports have indicated a possible link between low levels of BDNF and psychiatric conditions such as mood disorders and depression.
Anti-depressants, such as selective serotonin reuptake inhibitors (SSRIs), are typically prescribed to patients suffering from psychiatric conditions, such as depression and anxiety disorders. However, some patients are resistant to SSRIs. The time period required to determine whether a patient will respond positively or be resistant to SSRI treatment can be costly and lengthy.
Currently, there is a method for determining whether a patient is resistant to such types of treatment. The method is described in patent application PCT/U.S.2007/001560. However, there are currently no methods to predict who will not only be resistant to the treatment, but also who will be responsive.
Therefore, there is a need for new methods for determining whether a patient suffering from a condition that may be susceptible to treatment with a compound that activates the brain serotonin system is actually susceptible or resistant to treatment with the compound.